Rivers, Wetlands, and Climate Change

The rivers and wetlands of New Brunswick are important in many ways. They provide habitat for many species. They provide us with clean and safe drinking water. They are a source of recreation for many, and a source of inspiration for others. They are also prone to significant impacts as a result of climate change.

What may happen with rivers and wetlands?

Changes in precipitation patterns and temperature will result in significant extremes in groundwater levels. Spring floods will trend towards record high levels over the past, and more flooding in summer and autumn can be expected due to sever storms leading to greater runoff.

Record low levels will result from increased evaportion from surface waters nd less water being retained by the land following hard rains. Extended periods of drought will also lead to a decrease in water levels. The fluctuations in river conditions, and the accompanying increase in water temperatures, will endanger many of our aquatic species, like Atlantic Salmon and brook trout, which rely on specific water conditions to thrive.

The rapid rise and fall of river levels will contribute to erosion of river banks. Areas currently covered by water will be exposed to heat and air, drying them out, and making them more susceptible to erosion when higher waters return.

The threat to wetlands and lakes lies largely in evapotranspiration, the loss of water to the air because of heat and dry conditions. Again this will result in lower water levels. Some wetlands may dry up altogether, resulting in loss of habitat to many species and possible extirpations. A side effect to the drying out of peat bogs is that it will increase the amount of carbon released into the atmosphere, thus adding to the problems of climate change.

Groundwater will face an increased risk of pollution in the future. Less predictable growing conditions may necessitate the use of more pesticides and fertilizers for farming and forestry, and these contaminants will be more likely to enter the water sources when strong storms cause runoff.

What are the possible solutions for protecting our rivers and wetlands?

The greatest protection for rivers and wetlands is the trees and other plantlife that surround them. These natural buffers play many roles. The canopy cover of the trees over the the water helps to regulate the water's temperatuire by providing shade. Thick grrowth of understory plants lessens the mpact of rain on the ground, slowing the water so that it has a greater chance of seeping into the griound instead of running off quickly into the rivers and streams. Forested areas help slow the rate of snowmelt, allowing much of the melted water to seep into the soil, gradually adding to groundwater and preventing extreme floods. Plant root systems also strengthen river banks, providing some insurance against increased erosion. Plants also provide a filter against pollutants entering the water.

Increased riparian buffers will help conserve these protective functions for rivers and wetlands. We may also need to restore buffers in areas where development has eliminated them.

What needs to happen in New Brunswick?

Buffer zones of trees, shrubs and plants conserved or restored along the entire length of streams, rivers and wetlands will mitigate the impacts of built development, agriculture, logging or other development. To provide the best protective function, these buffer zones should not permit any development or removal of trees.

Restoration of riparian or wetland buffers could include heightened berms between wet areas and development to slow the runoff from these areas, and the planting of trees along exposed areas to strengthen river banks and provide shade.

Through forest management, special attention through policy or regulation to maintaining forest canopy cover over small headwater streams and seasonal pools will help regulate water flow into larger streams and rivers and moderate water temperatures.

Special conservation attention given to conserving peat bogs will allow them to continue to store high levels of carbon in their peat, since they will release CO2 into the atmosphere when they are drained or the peat is harvested.